While all trees provide oxygen and help stabilize the climate, redwood trees are truly climate champions. “Ancient redwood forests store at least three times more carbon above ground than any other forests on earth,” according to RCCI findings. Two mature redwoods remove and store roughly 1,600 tons of carbon from the atmosphere, as much as the average American produces in a lifetime through his/her carbon dioxide emissions (CO2).
Forests cover roughly 30 percent of the earth’s surface and store more carbon than is contained in the entire atmosphere!
How do forests pull carbon out of the air? Through the fundamental life process of photosynthesis, all plants capture energy from sunlight to convert CO2 and water into the building blocks for growth. During photosynthesis, plants pull in CO2 and release oxygen into the atmosphere, supplying the entire animal kingdom.
Coast redwoods in particular are exceptional at storing carbon and releasing oxygen. Here’s why:
- Their enormous size, fast — and continuing — growth, and longevity. Attaining heights up to 350 feet and trunk diameters more than 24 feet, redwoods can live more than 2,000 years. We now know that redwoods continue to grow as long as they live, packing on the girth, growing new tops after windstorms blow off old ones and sprouting millions of new needles. Thus they continue to pull in CO2 and release oxygen as they age — long after they attain their full height.
- Slow rates of decay. When trees are cut or die, they stop pulling in carbon. As they decay, they begin releasing their stored carbon back into the atmosphere. Different tree species have different life spans and decay at different rates. Once again, redwoods are extraordinary. After an old-growth redwood dies, it can take many centuries to decompose and release its stored carbon.
Redwoods help conserve water
Redwoods also play a critical role in local watersheds, both in terms of water quality and water supply. Here’s how:
- The vast root systems of redwoods carpet our local watersheds to help prevent erosion and their deep loamy soils act as natural water filtration and storage systems. Forest soils act like giant sponges, soaking up rainwater as it falls, and slowly releasing it throughout the dry season. In addition, redwoods that grow along streams provide shade, keeping the water cool for native fish.
- They use fog as their primary water source during times of year when rain is most scarce in northern California. As the fog rolls in off the coast and creeps through the redwood canopy, it condenses on millions of redwood needles. This fog-drip is captured by redwood roots, which spread out widely near the surface of the soil. It is estimated that fog-drip supplies 30 to 40 percent of the water that redwoods require to grow!
- Fog-drip from redwoods also supplies summer water to fish and humans. Spencer Robert Sawaske, a Stanford researcher, measured fog-drip from individual trees in the Santa Cruz Mountains during the 2013 dry season. He found that older redwoods and Douglas firs on the Pacific Coast side near the ridgetops produced the most fog-drip: up to 38 inches recorded over 2.5 months! He also found that this fogdrip soaked into the ground and replenished stream flow.
During the current drought in California, the local redwood forest continues to tap fog as a water source, and its deep, loamy soils slowly release the water it captured from earlier rain. No doubt the redwood forest has softened the effects of the current drought.
How can we help redwoods survive climate disruption?
Forest scientists emphasize the need to increase the adaptive ability of forests to withstand climate disruption. To help redwood forests, we can:
- minimize soil disturbance,
- protect and buffer old-growth reserves,
- reduce forest road densities,
- increase wildlife connectivity.
Sempervirens Fund is forging ahead with all of these stewardship activities in San Vicente Redwoods, which connects 27,500 acres of contiguous protected land and shelters some 90 ancient redwoods that will be protected in special reserves.
By acquiring, protecting and caring for local redwood forests, Sempervirens Fund helps manage redwood ecosystems to increase their resilience to drought, accelerating climate change and human disturbances. We are working with our donors and partners to create the Great Park to ensure that redwoods continue their extraordinary contributions here for thousands of years to come.